Barcelona: Two-time world champion Fernando Alonso was airlifted to hospital after crashing his McLaren on Sunday`s final morning of the second pre-season test in Barcelona.

The Spaniard had managed just 20 laps on another troubled morning for the struggling McLaren-Honda partnership when he crashed into the wall between turns three and four at the Circuit de Catalunya.

"Fernando was driven to the circuit`s medical centre where the circuit`s doctors gave him first aid," McLaren said in a statement.

"He was conscious and spoke with the doctors.

"However, as per usual procedure in such circumstances, he was then airlifted to hospital where he is undergoing precautionary checks."

Alonso`s agent Luis Garcia Abad added that the 33-year-old would remain in hospital under observation for the next 24 to 48 hours.

The crash brought McLaren`s day to an end to round off a disastrous test that has left them well behind every other team on the grid in terms of mileage in testing with just 203 laps completed under a month until the first Grand Prix of the new season.

The other Spanish driver on show, Carlos Sainz Junior, also crashed at the same part of the track where Alonso went off, but was able to walk away from a check-up at the medical centre unharmed.

Lotus were again fastest as Frenchman Romain Grosjean followed teammate Pastor Maldonado`s example on days one and three in a time of 1min 24.067sec on the supersoft tyres.

However, the day arguably belonged to defending world champions Mercedes as Nico Rosberg completed another mammoth 131-lap run and was under three tenths of a second behind Grosjean on the slower medium tyre compound.

Daniil Kyvat was third quickest for Red Bull, whilst Sebastian Vettel was down in seventh fastest during his 76 laps in the Ferrari.

The teams will return to the track in the Catalan capital for a final four-day test from Thursday to finalise preparations before the first race of the season at the Australian Grand Prix in Melbourne on March 15.